Charging apparatus and operating method thereof

1. A charging apparatus configured to charge a battery device, the charging apparatus comprising: a power conversion circuit configured to provide a charging power to charge the battery device; a feedback circuit coupled to the power conversion circuit and configured to generate a feedback signal associated with the charging power for the power conversion circuit, wherein the power conversion circuit correspondingly adjusts the charging power according to the feedback signal; an identifier control circuit coupled to the feedback circuit and configured to receive identifier information from the battery device and determine whether to control the feedback circuit to change the feedback signal according to the identifier information to dynamically adjust the charging power to adapt to the battery device; and a low voltage trickle control circuit coupled to the feedback circuit and the power conversion circuit and configured to determine whether to control the feedback circuit to change the feedback signal according to a voltage of the charging power to cause the power conversion circuit to trickle charge the battery device, wherein when the low voltage trickle control circuit controls the feedback circuit to change the feedback signal, the feedback circuit ignores control of the identifier control circuit, wherein the low voltage trickle control circuit comprises: a voltage detecting circuit coupled to the power conversion circuit and configured to detect the charging power to obtain a detecting voltage; and a voltage comparing circuit coupled to the voltage detecting circuit to receive the detecting voltage and configured to compare the detecting voltage with a threshold voltage to obtain a comparison result, wherein the voltage comparing circuit determines whether to control the feedback circuit to change the feedback signal according to the comparison result.

2. The charging apparatus according to claim 1 , wherein the feedback circuit comprises: a pull-up resistor circuit comprising a first terminal coupled to the power conversion circuit to receive the charging power, wherein a second terminal of the pull-up resistor circuit provides a divided voltage associated with the charging power; and a pull-down resistor circuit comprising a first terminal and a second terminal respectively coupled to the second terminal of the pull-up resistor circuit and a reference voltage, wherein when neither the low voltage trickle control circuit nor the identifier control circuit controls the pull-down resistor circuit, the pull-down resistor circuit has a first resistance value, the pull-down resistor circuit has a second resistance value based on control of the identifier control circuit, the pull-down resistor circuit has a third resistance value based on control of the low voltage trickle control circuit, and when the low voltage trickle control circuit controls the pull-down resistor circuit, the pull-down resistor circuit ignores control of the identifier control circuit.

3. The charging apparatus according to claim 2 , wherein the pull-down resistor circuit comprises: a first pull-down resistor comprising a first terminal coupled to the second terminal of the pull-up resistor circuit; a second pull-down resistor comprising a first terminal coupled to a second terminal of the first pull-down resistor, wherein a second terminal of the second pull-down resistor is coupled to the reference voltage; a first switch comprising a first terminal and a second terminal respectively coupled to the first terminal and the second terminal of the first pull-down resistor, wherein a control terminal of the first switch is controlled by the identifier control circuit; and a second switch comprising a first terminal and a second terminal respectively coupled to the first terminal of the first pull-down resistor and the second terminal of the second pull-down resistor, wherein a control terminal of the second switch is controlled by the low voltage trickle control circuit.

4. The charging apparatus according to claim 1 wherein the identifier control circuit comprises: a first resistor comprising a first terminal coupled to a first voltage, wherein a second terminal of the first resistor controls the feedback circuit; and a switch comprising a first terminal and a second terminal respectively coupled to the second terminal of the first resistor and a second voltage, wherein a control terminal of the switch is controlled by the identifier information of the battery device.

5. The charging apparatus according to claim 4 , wherein the identifier control circuit further comprises: a second resistor comprising a first terminal coupled to the control terminal of the switch, wherein a second terminal of the second resistor is coupled to the battery device to receive the identifier information; and a third resistor comprising a first terminal coupled to the first terminal of the second resistor, wherein a second terminal of the third resistor is coupled to the second voltage.

6. The charging apparatus according to claim 5 , wherein the identifier control circuit further comprises: an electrostatic discharge protection member comprising a first terminal coupled to the second terminal of the second resistor, wherein a second terminal of the electrostatic discharge protection member is coupled to the second voltage.

7. The charging apparatus according to claim 1 , wherein the voltage comparing circuit comprises: a comparator comprising a first input terminal for receiving the threshold voltage, wherein a second input terminal of the comparator is coupled to the voltage detecting circuit to receive the detecting voltage; a first resistor comprising a first terminal coupled to a first voltage, wherein a second terminal of the first resistor is coupled to an output terminal of the comparator; a second resistor comprising a first terminal coupled to the second terminal of the first resistor, wherein a second terminal of the second resistor controls the feedback circuit; and a capacitor comprising a first terminal and a second terminal respectively coupled to the second terminal of the second resistor and a second voltage.

8. The charging apparatus according to claim wherein the voltage detecting circuit comprises: a first resistor comprising a first terminal coupled to a first voltage, wherein a second terminal of the first resistor is coupled to the voltage comparing circuit to provide the detecting voltage; a second resistor comprising a first terminal coupled to the second terminal of the first resistor, wherein a second terminal of the second resistor is coupled to a second voltage; and a capacitor comprising a first terminal and a second terminal respectively coupled to the second terminal of the first resistor and the second voltage.

9. The charging apparatus according to claim 1 , wherein the low voltage trickle control circuit further comprises: a resistor comprising a first terminal coupled to a first voltage, wherein a second terminal of the resistor is coupled to the voltage comparing circuit to provide the threshold voltage; and a capacitor comprising a first terminal and a second terminal respectively coupled to the second terminal of the resistor and a second voltage.

10. An operating method of a charging apparatus configured to charge a battery device, the operating method comprising: providing, by a power conversion circuit, a charging power to charge the battery device; generating, by a feedback circuit, a feedback signal associated with the charging power for the power conversion circuit, wherein the power conversion circuit correspondingly adjusts the charging power according to the feedback signal; receiving, by an identifier control circuit, identifier information from the battery device; determining, by the identifier control circuit, whether to control the feedback circuit to change the feedback signal according to the identifier information to dynamically adjust the charging power to adapt to the battery device; and determining, by a low voltage trickle control circuit, whether to control the feedback circuit to change the feedback signal according to a voltage of the charging power to cause the power conversion circuit to trickle charge the battery device, wherein when the low voltage trickle control circuit controls the feedback circuit to change the feedback signal, the feedback circuit ignores control of the identifier control circuit, wherein the step of determining whether to control the feedback circuit to change the feedback signal according to the voltage of the charging power to cause the power conversion circuit to trickle charge the battery device comprises: detecting the charging power to obtain a detecting voltage; comparing the detecting voltage with a threshold voltage to obtain a comparison result; and determining whether to control the feedback circuit to change the feedback signal according to the comparison result.